High-temperature-resistant and corrosion-resistant conductive coating and preparation method thereof

Abstract

The invention provides a high-temperature-resistant and corrosion-resistant conductive coating which is prepared from the following components in parts by weight: 28-40 parts of conductive filler, 80-100 parts of resin, 3-15 parts of diluent and 1.5-3 parts of assistant, and the high-temperature-resistant and corrosion-resistant conductive coating is obtained by compounding and curing the components. Firstly, silver-coated copper powder, silver alginate sol and a sodium phosphate solution are adopted for preparing corrosion-resistant conductive filler; secondly, mixing any one or more of methylbenzene, dimethylbenzene, n-butyl alcohol and propylene glycol methyl ether acetate to obtain a diluent; and finally, uniformly mixing the prepared corrosion-resistant conductive filler, resin and a diluent to obtain conductive slurry, spraying the conductive slurry to the surface of a base material, and performing high-temperature baking to obtain the high-temperature-resistant corrosion-resistant conductive coating. The conductivity of the prepared conductive coating ranges from 40 m omega / square to 350 m omega / square, and after the conductive coating is placed in the environment of 300 DEG C for 500 h, the change of the conductivity and the adhesive force is not larger than 5%; and the salt spray corrosion resistance time in an acid salt spray environment is prolonged from 1-2 days to 42 days.

Description

Technical Field

[0001] The present invention belongs to the technical field of conductive coatings, and in particular relates to a high temperature resistant and corrosion resistant conductive coating and a preparation method thereof. Background Art

[0002] At present, in order to solve the edge scattering problem existing in the surface gaps and step designs of aircraft, a corrosion-resistant and conductive material with excellent conductivity has been designed to achieve electrical continuity on the aircraft surface and effectively control the scattering problem. However, the existing conductive materials are coated on metal substrates and are prone to electrochemical corrosion in high temperature, high humidity or high salt environments, forming a potential difference, which limits the effect of reducing current loss. Therefore, it is urgent to explore a corrosion-resistant conductive material.

[0003] In the application number CN202311500682.8, the patent name is: A corrosion-resistant and high-conductivity conductive coating and its preparation method and application, which discloses the use of silver / polyaniline composite materials to dope the network structure in the resin to improve the density and corrosion resistance of the coating, but the conductive coating prepared by it cannot meet the requirements of relevant temperature resistance performance; in the application number CN202211485418.7, the patent name is: A conductive material composition, conductive slurry and its preparation method, which discloses that the carbon nanotubes are more regular and evenly distributed through the point contact effect between the carbon nanotubes and the auxiliary conductive material. Cloth, thereby improving the electrical properties of the conductive material, but the conductive material prepared thereby has low conductivity, and the resistance value is in the kilo-ohm level, which cannot meet the conductive capacity of the equipment application; the application number is CN202310031476.0, and the patent name is: A corrosion-resistant conductive coating and its preparation method and application, which discloses that by embedding silver crystals in the mesh structure of the resin reaction, the dispersion of polyaniline and the penetration of free electrons in the coating are achieved, so as to achieve the purpose of corrosion resistance, but it cannot achieve complete corrosion resistance by adding zinc phosphate powder and wrapping with resin. When the resin is destroyed, the silver powder will be exposed, thereby reducing the corrosion resistance.

[0004] In view of this, this invention is proposed. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a high temperature resistant and corrosion resistant conductive coating, which can solve the problem of poor corrosion resistance of the existing conductive coating while taking into account the temperature resistance.

[0006] The purpose of the present invention is to be solved by the following technical solutions:

[0007] In one aspect, the present invention provides a high temperature resistant and corrosion resistant conductive coating, wherein the conductive coating comprises the following components in parts by weight:

[0008] 28-40 parts of conductive filler, 80-100 parts of resin, 3-15 parts of diluent, 1.5-3 parts of auxiliary agent, and the high temperature and corrosion resistant conductive coating are obtained by compounding and curing the above components.

[0009] Furthermore, the thickness of the conductive coating is 20-60 μm.

[0010] Furthermore, the conductive filler is composed of silver-coated copper powder, sodium phosphate solution and alginate silver sol, and the mass ratio of the silver-coated copper powder, sodium phosphate solution and alginate silver sol in the conductive filler is 0.5:1:5.

[0011] Furthermore, the auxiliary agent consists of a wetting and dispersing agent and an organic bentonite, and the mass ratio of the wetting and dispersing agent to the organic bentonite in the auxiliary agent is 2:1.

[0012] Furthermore, the wetting and dispersing agent is BYK-110 dispersant.

[0013] Furthermore, the resin is any one of epoxy-modified silicone resin, silicone resin, polyurethane-modified silicone resin or polyimide resin.

[0014] Furthermore, the diluent is any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate.

[0015] On the other hand, the present invention provides a method for preparing a high temperature resistant and corrosion resistant conductive coating, wherein the preparation method is carried out according to the component raw materials included in the high temperature resistant and corrosion resistant conductive coating and the corresponding weight parts of the component raw materials, and specifically comprises the following steps:

[0016] S1. preparing conductive filler: preparing corrosion-resistant conductive filler by using silver-coated copper powder, alginate silver sol and sodium phosphate solution;

[0017] S2. Prepare a diluent: mix any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate, and stir and disperse at a speed of 1500 r / min for a dispersion time of 10 to 15 min to obtain a diluent;

[0018] S3. Prepare a high temperature and corrosion resistant conductive coating: evenly mix the prepared corrosion resistant conductive filler, resin and diluent to obtain a conductive slurry, spray the conductive slurry onto the surface of the substrate, and obtain a high temperature and corrosion resistant conductive coating after high temperature baking.

[0019] Furthermore, the specific steps of preparing the conductive filler in step S1 include:

[0020] S1.1. Place the silver-coated copper powder weighed in proportion in an oven at 150-250℃ for 1-5 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0021] S1.2, weighing silver alginate sol and sodium phosphate solution in proportion, placing them in a container, dispersing and stirring them for the first time, adding the silver-coated copper powder coated with the pre-oxidized film into the container, dispersing and stirring them for the second time, and obtaining a sol solution,

[0022] The speeds used in the first dispersing and stirring and the second dispersing and stirring are both 500-1500 r / min, and the dispersing time is 5-20 min.

[0023] S1.3, after the obtained sol solution is left for 1 hour, it is placed in a vacuum oven for drying at 200-300°C for 1-5 hours to obtain a gel.

[0024] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 500-800°C at a rate of 3°C / min, and keep it warm for 2-8 hours to obtain a corrosion-resistant conductive filler.

[0025] Furthermore, the specific steps of preparing the high temperature resistant and corrosion resistant conductive coating in step S3 include:

[0026] First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a speed of 1500r / min and a dispersion time of 10 to 15min. After being mixed evenly, a conductive slurry is obtained. The conductive slurry is sprayed onto the surface of the substrate using a spray gun with a caliber of 3 to 5mm.

[0027] Then, the substrate sprayed with the conductive paste was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0028] Finally, the temperature is raised to 180-250° C. and cured for 3-6 hours to obtain a high temperature resistant and corrosion resistant conductive coating.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The present invention adopts a double coating process of pre-oxidation and sol-gel to form two coating layers on the surface of the silver-coated copper powder, which has good electrical conductivity and better salt spray corrosion resistance and temperature resistance. The prepared conductive coating has a conductivity of 40 to 350 mΩ / □, which meets the conductivity requirements of equipment applications. At the same time, after being placed in a 300°C environment for 500 hours, the conductivity and adhesion of the conductive coating change by no more than 5%; in an acidic salt spray environment, the salt spray corrosion resistance time of the conductive coating is extended from 1 to 2 days to 42 days;

[0031] 2. The conductive coating formed by the present invention adopts air compression spraying technology, the coating has good coating density, and the preparation method is environmentally friendly, simple and low-cost;

[0032] 3. The high temperature resistant and corrosion resistant conductive coating prepared by the method of the present invention has good corrosion resistance and can work for more than 36 months under acidic salt spray conditions of pH = 3.5, and can also serve for a long time in a high temperature environment of 300°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are incorporated in and constitute a part of this specification and, together with the description, serve to explain the principles of the present invention.

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] Figure 1 It is a flow chart of the method for preparing the high temperature resistant and corrosion resistant conductive coating of the present invention;

[0036] Figure 2 It is a schematic diagram of the structure of the high temperature resistant and corrosion resistant conductive coating of the present invention;

[0037] Wherein, a is a photo of the high temperature resistant and corrosion resistant conductive coating prepared in Example 1;

[0038] b is a photo of the high temperature resistant and corrosion resistant conductive coating prepared in Example 2;

[0039] c is a photo of the high temperature resistant and corrosion resistant conductive coating prepared in Example 3;

[0040] d is a photo of the high temperature resistant and corrosion resistant conductive coating prepared in Example 4;

[0041] e is a photo of the high temperature resistant and corrosion resistant conductive coating prepared in Example 5. DETAILED DESCRIPTION

[0042] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples consistent with some aspects of the present invention as detailed in the appended claims.

[0043] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0044] According to an embodiment of the present invention, the present invention provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components in parts by weight: 28 to 40 parts of conductive filler, 80 to 100 parts of resin, 3 to 15 parts of diluent, and 1.5 to 3 parts of auxiliary agent. The high temperature resistant and corrosion resistant conductive coating is obtained by compounding and curing the above components.

[0045] According to an embodiment of the present invention, the thickness of the conductive coating is 20-60 μm.

[0046] According to an embodiment of the present invention, the conductive filler is composed of silver-coated copper powder, sodium phosphate solution and alginate silver sol, and the mass ratio of the silver-coated copper powder, sodium phosphate solution and alginate silver sol in the conductive filler is 0.5:1:5.

[0047] According to an embodiment of the present invention, the auxiliary agent consists of a wetting and dispersing agent and an organic bentonite, and the mass ratio of the wetting and dispersing agent to the organic bentonite in the auxiliary agent is 2:1.

[0048] According to an embodiment of the present invention, the wetting and dispersing agent is BYK-110 dispersant.

[0049] According to an embodiment of the present invention, the resin is any one of epoxy-modified silicone resin, silicone resin, polyurethane-modified silicone resin or polyimide resin.

[0050] According to an embodiment of the present invention, the diluent is any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate.

[0051] According to an embodiment of the present invention, the present invention provides a method for preparing a high temperature resistant and corrosion resistant conductive coating, and the preparation method is carried out according to the component raw materials included in the high temperature resistant and corrosion resistant conductive coating and the corresponding weight parts of the component raw materials, and specifically comprises the following steps:

[0052] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0053] S1.1. Place the silver-coated copper powder weighed in proportion into an oven at 150-250°C for 1-5 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0054] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 500-1500 r / min and a dispersion time of 5-20 min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container for the second dispersion stirring at a speed of 500-1500 r / min and a dispersion time of 5-20 min to obtain a sol solution.

[0055] S1.3. After the obtained sol solution is left for 1 hour, it is placed in a vacuum oven for drying. The vacuum oven temperature is 200-300°C and the insulation time is 1-5 hours to obtain a gel.

[0056] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 500-800°C at a rate of 3°C / min, and keep it warm for 2-8 hours to obtain a corrosion-resistant conductive filler.

[0057] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0058] S2. Prepare a diluent: mix any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate, stir and disperse at a speed of 1500 r / min for a dispersion time of 10 to 15 min, and obtain a diluent after stirring evenly.

[0059] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0060] First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 10-15min. After mixing evenly, a conductive slurry is obtained. A 3-5mm caliber spray gun is used to spray the conductive slurry onto the surface of the substrate. The air compressed spraying process parameters are: spraying pressure 0.3-0.5MPa, spraying distance 20-50cm, spraying angle 30-90°, and spray gun moving speed 15-60cm / s.

[0061] Then, the substrate sprayed with the conductive paste was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0062] Finally, the temperature is raised to 180-250° C. and cured for 3-6 hours to obtain a high temperature resistant and corrosion resistant conductive coating.

[0063] According to an embodiment of the present invention, the high temperature resistant and corrosion resistant conductive coating of the present invention is sprayed on a titanium alloy substrate or other metal substrate to form a long-term heat resistant and salt spray corrosion resistant conductive coating thereon.

[0064] In order to further verify the efficacy of the high temperature resistant and corrosion resistant conductive coating of the present invention, the following examples are provided for further explanation:

[0065] Example 1

[0066] This embodiment 1 provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components in parts by weight: 28 parts of conductive filler, 80 parts of resin, 3 parts of diluent, and 1.5 parts of additive.

[0067] Among them, the conductive filler contains 2.2 parts of silver-coated copper powder, 4.3 parts of sodium phosphate solution, and 21.5 parts of alginate silver sol;

[0068] The resin adopts epoxy modified silicone resin;

[0069] The diluent is toluene, 3 parts of toluene;

[0070] The additive contains 1 part of wetting and dispersing agent and 0.5 part of organic bentonite.

[0071] A method for preparing a high temperature resistant and corrosion resistant conductive coating of the present invention specifically comprises the following steps:

[0072] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0073] S1.1. Place the silver-coated copper powder weighed in proportion into a 250°C oven and keep it warm for 1 hour to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0074] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 500 r / min and a dispersion time of 20 min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container and perform the second dispersion stirring at a speed of 500 r / min and a dispersion time of 20 min to obtain a sol solution.

[0075] S1.3. After the obtained sol solution is placed at room temperature for 1 hour, it is placed in a vacuum oven for drying. The vacuum oven temperature is 300°C and the insulation time is 1 hour to obtain a gel.

[0076] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 500°C at a rate of 3°C / min, and keep it warm for 8 hours to obtain a corrosion-resistant conductive filler.

[0077] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0078] S2. Prepare a diluent: weigh 3 parts by weight of toluene as a diluent.

[0079] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0080] First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 10min. After mixing evenly, a conductive slurry is obtained. A 3-5mm caliber spray gun is used to spray the conductive slurry onto the surface of the titanium alloy substrate. The air compressed spraying process parameters are: spraying pressure 0.3MPa, spraying distance 20cm, spraying angle 30°, and spray gun moving speed 15cm / s.

[0081] Then, the substrate sprayed with the conductive paste was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0082] Finally, after heating to 180°C and curing for 6 hours, a high temperature and corrosion resistant conductive coating with a thickness of 20 μm was obtained.

[0083] Example 2

[0084] This embodiment 2 provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components in parts by weight: 32 parts of conductive filler, 85 parts of resin, 4 parts of diluent, and 1.8 parts of additive.

[0085] Among them, the conductive filler contains 2.5 parts of silver-coated copper powder, 4.9 parts of sodium phosphate solution, and 24.6 parts of alginate silver sol;

[0086] The resin adopts silicone resin;

[0087] The diluent is a mixture of toluene, xylene and n-butanol or propylene glycol methyl ether acetate, wherein toluene is 1 part, xylene is 1 part, and n-butanol or propylene glycol methyl ether acetate is 2 parts;

[0088] The additive contains 1.2 parts of wetting and dispersing agent and 0.6 parts of organic bentonite.

[0089] A method for preparing a high temperature resistant and corrosion resistant conductive coating of the present invention specifically comprises the following steps:

[0090] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0091] S1.1. Place the silver-coated copper powder weighed in proportion into a 230°C oven and keep it warm for 2 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0092] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 800 r / min and a dispersion time of 18 min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container and perform the second dispersion stirring at a speed of 800 r / min and a dispersion time of 18 min to obtain a sol solution.

[0093] S1.3. After the obtained sol solution is placed at room temperature for 1 hour, it is placed in a vacuum oven for drying at a temperature of 280°C and kept warm for 2 hours to obtain a gel.

[0094] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 550°C at a rate of 3°C / min, and keep it warm for 7 hours to obtain a corrosion-resistant conductive filler.

[0095] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0096] S2. Prepare a diluent: stir and disperse toluene, xylene and n-butanol or propylene glycol methyl ether acetate in proportion at a rotation speed of 1500 r / min for a dispersion time of 10 min, and mix and stir evenly to obtain a diluent.

[0097] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0098] Firstly, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 12min to obtain a conductive slurry. The conductive slurry is sprayed onto the surface of the titanium alloy substrate using a 3-5mm caliber spray gun. The air compressed spraying process parameters are: spraying pressure 0.35MPa, spraying distance 25cm, spraying angle 50°, and spray gun moving speed 25cm / s.

[0099] Then, the titanium alloy substrate sprayed with the conductive slurry was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0100] Finally, after heating to 200°C and curing for 5 hours, a high temperature and corrosion resistant conductive coating with a thickness of 25 μm was obtained.

[0101] Example 3

[0102] This embodiment 3 provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components in parts by weight: 35 parts of conductive filler, 90 parts of resin, 7 parts of diluent, and 2.2 parts of additive.

[0103] Among them, the conductive filler contains 2.7 parts of silver-coated copper powder, 5.4 parts of sodium phosphate solution, and 26.9 parts of alginate silver sol;

[0104] The resin adopts silicone resin;

[0105] The diluent is a mixture of toluene, xylene and n-butanol or propylene glycol methyl ether acetate, wherein toluene is 2 parts, xylene is 2 parts, and n-butanol or propylene glycol methyl ether acetate is 3 parts;

[0106] The additive contains 1.4 parts of wetting and dispersing agent and 0.8 parts of organic bentonite.

[0107] A method for preparing a high temperature resistant and corrosion resistant conductive coating of the present invention specifically comprises the following steps:

[0108] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0109] S1.1. Place the silver-coated copper powder weighed in proportion in a 210°C oven and keep it warm for 3 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0110] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 1000r / min and a dispersion time of 20min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container and perform the second dispersion stirring at a speed of 1000r / min and a dispersion time of 20min to obtain a sol solution.

[0111] S1.3. After the obtained sol solution was placed at room temperature for 1 hour, it was placed in a vacuum oven for drying at a temperature of 260°C and the heat preservation time was 3 hours to obtain a gel.

[0112] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 650°C at a rate of 3°C / min, and keep it warm for 5 hours to obtain a corrosion-resistant conductive filler.

[0113] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0114] S2. Prepare a diluent: stir and disperse toluene, xylene and n-butanol or propylene glycol methyl ether acetate in proportion at a rotation speed of 1500 r / min for a dispersion time of 12 min, and mix and stir evenly to obtain a diluent.

[0115] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0116] First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 12min. After mixing evenly, a conductive slurry is obtained. A 3-5mm caliber spray gun is used to spray the conductive slurry onto the surface of the titanium alloy substrate. The air compressed spraying process parameters are: spraying pressure 0.4MPa, spraying distance 30cm, spraying angle 70°, and spray gun moving speed 35cm / s.

[0117] Then, the titanium alloy substrate sprayed with the conductive slurry was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0118] Finally, after heating to 210°C and curing for 4.5 hours, a high temperature resistant and corrosion resistant conductive coating with a thickness of 35 μm was obtained.

[0119] Example 4

[0120] This embodiment 4 provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components by weight: 38 parts of conductive filler, 95 parts of resin, 10 parts of diluent, and 2.7 parts of additive. Among them, the conductive filler comprises 2.9 parts of silver-coated copper powder, 5.9 parts of sodium phosphate solution, and 29.2 parts of alginate silver sol;

[0121] The resin adopts polyurethane modified silicone resin;

[0122] The diluent is a mixture of xylene and n-butanol or propylene glycol methyl ether acetate, wherein xylene is 4 parts and n-butanol or propylene glycol methyl ether acetate is 6 parts;

[0123] The additive contains 1.8 parts of wetting and dispersing agent and 0.9 parts of organic bentonite.

[0124] A method for preparing a high temperature resistant and corrosion resistant conductive coating of the present invention specifically comprises the following steps:

[0125] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0126] S1.1. Place the silver-coated copper powder weighed in proportion in an oven at 180°C for 4 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0127] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 1200 r / min and a dispersion time of 15 min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container and perform the second dispersion stirring at a speed of 1200 r / min and a dispersion time of 15 min to obtain a sol solution.

[0128] S1.3. After the obtained sol solution was placed at room temperature for 1 hour, it was placed in a vacuum oven for drying at a temperature of 230°C and the insulation time was 4 hours to obtain a gel.

[0129] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 700°C at a rate of 3°C / min, and keep it warm for 4 hours to obtain a corrosion-resistant conductive filler.

[0130] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0131] S2. Prepare a diluent: Mix xylene and n-butanol or propylene glycol methyl ether acetate in proportion, stir and disperse at a speed of 1500 r / min for a dispersion time of 14 min, and mix them evenly to obtain a diluent.

[0132] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0133] Firstly, the prepared corrosion-resistant conductive filler, resin and diluent were stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 14min. After being evenly mixed, a conductive slurry was obtained. A 3-5mm caliber spray gun was used to spray the conductive slurry onto the surface of the titanium alloy substrate. The air compressed spraying process parameters were: spraying pressure 0.45MPa, spraying distance 40cm, spraying angle 80°, and spray gun moving speed 45cm / s.

[0134] Then, the titanium alloy substrate sprayed with the conductive slurry was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0135] Finally, after heating to 220°C and curing for 4 hours, a high temperature and corrosion resistant conductive coating with a thickness of 45 μm was obtained.

[0136] Example 5

[0137] This embodiment 5 provides a high temperature resistant and corrosion resistant conductive coating, which comprises the following components by weight: 40 parts of conductive filler, 100 parts of resin, 15 parts of diluent, and 3 parts of additive. Among them, the conductive filler comprises 3 parts of silver-coated copper powder, 6 parts of sodium phosphate solution, and 31 parts of alginate silver sol;

[0138] The resin adopts polyimide resin;

[0139] The diluent is a mixture of xylene and n-butanol or propylene glycol methyl ether acetate, wherein xylene is 5 parts and n-butanol or propylene glycol methyl ether acetate is 10 parts;

[0140] The additive contains 2 parts of wetting and dispersing agent and 1 part of organic bentonite.

[0141] A method for preparing a high temperature resistant and corrosion resistant conductive coating of the present invention specifically comprises the following steps:

[0142] S1. Preparation of conductive filler: using silver-coated copper powder, alginate silver sol and sodium phosphate solution to prepare corrosion-resistant conductive filler.

[0143] S1.1. Place the silver-coated copper powder weighed in proportion into a 150°C oven and keep it warm for 6 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder.

[0144] S1.2. Place the silver alginate sol and sodium phosphate solution weighed in proportion in a container, use a high-speed shear mixer, and perform the first dispersion stirring at a speed of 1500r / min and a dispersion time of 5min. After stirring evenly, add the silver-coated copper powder coated with a pre-oxidized film into the container and perform the second dispersion stirring at a speed of 1500r / min and a dispersion time of 5min to obtain a sol solution.

[0145] S1.3. After the obtained sol solution was placed at room temperature for 1 hour, it was placed in a vacuum oven for drying at a temperature of 200°C and the insulation time was 5 hours to obtain a gel.

[0146] S1.4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 800°C at a rate of 3°C / min, and keep it warm for 2 hours to obtain a corrosion-resistant conductive filler.

[0147] At this point, the preparation of the corrosion-resistant conductive filler is completed.

[0148] S2. Prepare a diluent: Mix xylene and n-butanol or propylene glycol methyl ether acetate in proportion, stir and disperse at a speed of 1500 r / min for a dispersion time of 15 min, and mix them evenly to obtain a diluent.

[0149] S3. Prepare high temperature resistant and corrosion resistant conductive coating.

[0150] First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a rotation speed of 1500r / min and a dispersion time of 15min. After mixing evenly, a conductive slurry is obtained. A 3-5mm caliber spray gun is used to spray the conductive slurry onto the surface of the titanium alloy substrate. The air compressed spraying process parameters are: spraying pressure 0.5MPa, spraying distance 50cm, spraying angle 90°, and spray gun moving speed 60cm / s.

[0151] Then, the titanium alloy substrate sprayed with the conductive slurry was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours.

[0152] Finally, after heating to 250°C and curing for 3 hours, a high temperature resistant and corrosion resistant conductive coating with a thickness of 60 μm was obtained.

[0153] Performance Testing

[0154] The performance tests of the high temperature resistant and corrosion resistant conductive coatings prepared in Examples 1-5 were respectively carried out, the conductivity test was carried out using a four-probe, and the adhesion test was carried out according to GB / T 5210, and the test results are shown in Table 1. It can be concluded from the table that the material sheet resistance is ≤400mΩ / □. Due to the change in the thickness of the conductive layer, the sheet resistance changes in the embodiments are quite different, but the use requirements are met, and the adhesion is ≥15MPa, which meets the use requirements after the conductive material is coated.

[0155] Table 1 Conductivity test results of various embodiments

[0156]

[0157]

[0158] According to GB / T 1735, the heat resistance after 300℃ / 300h was evaluated, the appearance of the coating after heat resistance was visually inspected, the square resistance and the adhesion after heat resistance were tested. The results are shown in Table 2. It can be concluded from the table that the adhesion and conductivity before and after heat resistance do not change much, indicating that the conductive material has good temperature resistance.

[0159] Table 2 Test results of electrical conductivity of each embodiment after heat resistance

[0160]

[0161] According to GJB 150.11A, the acid salt spray performance test is carried out. The appearance is shown in the figure, and the conductivity is shown in Table 3. Figure 2It can be concluded that after the 1000h acid salt spray test, the conductive coatings prepared in each embodiment did not suffer from corrosion, and the conductive properties and adhesion did not change much.

[0162] Table 3 Test results of conductivity of each embodiment after 1000h acid salt spray resistance

[0163]

[0164] It can be seen that the high temperature resistant and corrosion resistant conductive coating prepared by the present invention has a conductivity of 40 to 350 mΩ / □, which meets the conductivity requirements of equipment applications. After being placed in a 300°C environment for 500 hours, the conductivity and adhesion change is no more than 5%; in an acidic salt spray environment, the salt spray corrosion resistance time is extended from 1 to 2 days to 42 days. The problem of poor corrosion resistance of the conductive coating is overcome, while taking into account the temperature resistance.

[0165] The above description is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention.

[0166] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A high temperature resistant and corrosion resistant conductive coating, characterized in that: The conductive coating comprises the following components in parts by weight: Conductive filler 28-40 parts, resin 80-100 parts, diluent 3-15 parts, additive 1.5-3 parts, The high temperature resistant and corrosion resistant conductive coating is obtained by compounding and curing the above components.

2. The high temperature and corrosion resistant conductive coating according to claim 1, characterized in that: The thickness of the conductive coating is 20-60 μm.

3. The high temperature and corrosion resistant conductive coating according to claim 1, characterized in that: The conductive filler consists of silver-coated copper powder, sodium phosphate solution and alginate silver sol, and the mass ratio of the silver-coated copper powder, sodium phosphate solution and alginate silver sol in the conductive filler is 0.5:1:

5.

4. The high temperature and corrosion resistant conductive coating according to claim 1, characterized in that: The auxiliary agent consists of a wetting and dispersing agent and organic bentonite, and the mass ratio of the wetting and dispersing agent to the organic bentonite in the auxiliary agent is 2:

1.

5. The high temperature and corrosion resistant conductive coating according to claim 4, characterized in that: The wetting and dispersing agent is BYK-110 dispersing agent.

6. The high temperature and corrosion resistant conductive coating according to claim 1, characterized in that: The resin is any one of epoxy-modified silicone resin, silicone resin, polyurethane-modified silicone resin or polyimide resin.

7. The high temperature and corrosion resistant conductive coating according to claim 1, characterized in that: The diluent is any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate.

8. A method for preparing a high temperature resistant and corrosion resistant conductive coating, characterized in that: The preparation method is based on the raw materials and weight proportions of the raw materials included in the high temperature resistant and corrosion resistant conductive coating according to any one of claims 1 to 7, and specifically comprises the following steps: S1. preparing conductive filler: preparing corrosion-resistant conductive filler by using silver-coated copper powder, alginate silver sol and sodium phosphate solution; S2. Prepare a diluent: mix any one or more of toluene, xylene, n-butanol and propylene glycol methyl ether acetate, and stir and disperse at a speed of 1500 r / min for a dispersion time of 10 to 15 min to obtain a diluent; S3. Prepare a high temperature and corrosion resistant conductive coating: evenly mix the prepared corrosion resistant conductive filler, resin and diluent to obtain a conductive slurry, spray the conductive slurry onto the surface of the substrate, and obtain a high temperature and corrosion resistant conductive coating after high temperature baking.

9. The method for preparing a high temperature resistant and corrosion resistant conductive coating according to claim 8, characterized in that: The specific steps of preparing the conductive filler in step S1 include: S1.

1. Place the silver-coated copper powder weighed in proportion in an oven at 150-250℃ for 1-5 hours to form a dense pre-oxidation film on the surface of the silver-coated copper powder. S1.2, weighing silver alginate sol and sodium phosphate solution in proportion, placing them in a container, dispersing and stirring them for the first time, adding the silver-coated copper powder coated with the pre-oxidized film into the container, dispersing and stirring them for the second time, and obtaining a sol solution, The speeds used in the first dispersing and stirring and the second dispersing and stirring are both 500-1500 r / min, and the dispersing time is 5-20 min. S1.3, after the obtained sol solution is left for 1 hour, it is placed in a vacuum oven for drying at 200-300°C for 1-5 hours to obtain a gel. S1.

4. Grind the obtained gel in a horizontal ball mill to obtain powder particles of 1000-1500 mesh. Then, put the ground powder particles into a vacuum furnace, heat it to 500-800°C at a rate of 3°C / min, and keep it warm for 2-8 hours to obtain a corrosion-resistant conductive filler.

10. The method for preparing a high temperature resistant and corrosion resistant conductive coating according to claim 8, characterized in that: The specific steps of preparing the high temperature resistant and corrosion resistant conductive coating in step S3 include: First, the prepared corrosion-resistant conductive filler, resin and diluent are stirred and dispersed at a speed of 1500r / min and a dispersion time of 10 to 15min. After being mixed evenly, a conductive slurry is obtained. The conductive slurry is sprayed onto the surface of the substrate using a spray gun with a caliber of 3 to 5mm. Then, the substrate sprayed with the conductive paste was placed in an oven and dried at 50°C for 2 hours, and then heated to 150°C and dried for 3 hours. Finally, the temperature is raised to 180-250° C. and cured for 3-6 hours to obtain a high temperature resistant and corrosion resistant conductive coating.

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